A process allocates unnamed giveable shared memory by using DosAllocSharedMem with the object name (pszName parameter) set to NULL and the memory options (flag parameter) set to OBJ_GIVEABLE. The process allocating the memory must pass a pointer to the shared memory to another process. This is typically done by using some form of interprocess communication, such as a queue or a named pipe.

If a process allocates shared memory with the OBJ_GIVEABLE option, this process can validate the pointer in another process with DosGiveSharedMem.

The following code fragment allocates 24576 bytes (24KB) of unnamed giveable shared memory:

    #define  INCL_DOSMEMMGR   /* Memory Manager values */
    #include <os2.h>

    APIRET  ulrc;
    PBYTE   pb;

    ulrc = DosAllocSharedMem((PVOID *) &pb,
                             (PSZ) NULL,
                             24576,        /* amount of memory */
                             fALLOC |
                             OBJ_GIVEABLE); /* giveable memory */

Once the memory is allocated, the allocating process can pass the memory pointer to a second process through interprocess communication. The second process need not use DosGetSharedMem; the second process can just use the shared memory.